Everyday Calculators & Converters
Discount Calculator
Two ways in: you know the discount and want the price, or you know the sale price and want the percent off.
- Runs in your browser
- Stacked discounts
What do you know?
Your discount
Your answer pops up here
Enter the original price and the discount or the sale price, then hit Calculate.
You pay
You changed something. Hit Calculate to refresh.
How it works
Two formulas, worked out at full precision and rounded only for display.
- You know the discount
- You pay = original × (1 − discount ÷ 100). With an extra discount, the second one applies to the reduced price: original × (1 − first ÷ 100) × (1 − extra ÷ 100). You save = original − what you pay.
- You know the sale price
- You save = original − sale price. Discount = saving ÷ original × 100.
- Effective discount
- For stacked offers, the effective discount is the total saving as a percentage of the original price: 20% then an extra 10% is 28%.
- Checks
- The original price must be more than 0 and discounts must be between 0 and 100%. A sale price above the original is a price rise, so it isn’t treated as a discount.
- Rounding
- Amounts show 2 decimals, or the decimals your chosen currency uses. Percentages show up to 2 decimals. Halves round up. The currency is used for formatting only.
Questions
How do I work out a percentage off?
Multiply the original price by the discount and divide by 100 to get the saving, then take the saving off the original. For 15% off 200, the saving is 30 and you pay 170. Choose “I know the discount %” and the calculator does both steps.
Is 20% off plus an extra 10% the same as 30% off?
No. The extra 10% comes off the already reduced price, so the two discounts multiply: 200 becomes 160 after 20%, then 144 after the extra 10%. That’s 28% off in total, not 30%. Use “+ Add an extra % off” to see the effective discount.
How do I find the discount from a sale price?
Subtract the sale price from the original price to get the saving, then divide the saving by the original price and multiply by 100. A price cut from 200 to 170 saves 30, which is 15% off.
How are the results rounded?
Everything is worked out at full precision and rounded only when shown: amounts to 2 decimals (or the decimals your chosen currency uses) and percentages to at most 2 decimals, with trailing zeros dropped. Halves round up.